/*******************************************************************************
 * Copyright (c) 2001, 2018 IBM Corp. and others
 *
 * This program and the accompanying materials are made available under
 * the terms of the Eclipse Public License 2.0 which accompanies this
 * distribution and is available at https://www.eclipse.org/legal/epl-2.0/
 * or the Apache License, Version 2.0 which accompanies this distribution and
 * is available at https://www.apache.org/licenses/LICENSE-2.0.
 *
 * This Source Code may also be made available under the following
 * Secondary Licenses when the conditions for such availability set
 * forth in the Eclipse Public License, v. 2.0 are satisfied: GNU
 * General Public License, version 2 with the GNU Classpath
 * Exception [1] and GNU General Public License, version 2 with the
 * OpenJDK Assembly Exception [2].
 *
 * [1] https://www.gnu.org/software/classpath/license.html
 * [2] http://openjdk.java.net/legal/assembly-exception.html
 *
 * SPDX-License-Identifier: EPL-2.0 OR Apache-2.0 OR GPL-2.0 WITH Classpath-exception-2.0 OR LicenseRef-GPL-2.0 WITH Assembly-exception
 *******************************************************************************/
package j9vm.test.hashCode;

import j9vm.test.hashCode.generator.HashCodeGenerator;
import j9vm.test.hashCode.generator.Lfsr;

public class LfsrAddingMaskGenerator extends HashCodeGenerator {

	Lfsr gen;

	public boolean seedChanged() {
		return false;
	}

	public LfsrAddingMaskGenerator(int initialSeed) {
		setSeed(initialSeed);
		gen = new Lfsr();
	}

	@Override
	public int processHashCode(int hashCode) {
		int processedHash = hashCode;
		int scrambler = seed;
		for (int i = 0; i < HashCodeGenerator.LFSR_CYCLES - 1; ++i) {
			if ((hashCode & (1 << i)) != 0) {
				processedHash += scrambler;
			}
			scrambler = gen.runLfsr(scrambler, 1);
		}
		return processedHash;
	}
}
